1. Field of the Invention
This invention relates to cartridge pullers, in particular to pullers of spool valves which comprise cartridge cores and sleeves and more specifically to pullers of Moen type single handle mixing valve cartridges used in showers and faucets, and a method of use thereof.
2. Description of Prior Art
Showers and faucets are often fitted with single handle mixing valves which serve to regulate the temperature and flow of water. These valves are commonly referred to as cartridges and fall into the general classification of spool valves which regulate flow and mixture of fluids by use of a slidable and/or rotatable core fitted inside a sleeve. The core and sleeve generally contain apertures through which the fluids flow. The core of the single handle mixing valve contains a thread for the attachment of a handle used to operate the valve. There are several types of single handle mixing valves and one of the most commonly used is manufactured by Moen Incorporated.
The Moen cartridge has been on the market for many years and is now manufactured by other companies as well. All of the cartridges manufactured to the Moen single handle mixing valve design are generally referred to as Moen cartridges. In the Moen cartridge, water flow is controlled by moving the core in and out of the sleeve, and temperature is controlled by twisting the core clockwise or counterclockwise. The cartridge is installed in a brass housing located in the body of a faucet or behind the wall of a shower. After installation, a handle is attached to the core to regulate water flow and temperature.
Moen cartridges are generally durable and last for many years before replacement is required. During the active life of the cartridge, mineral sediment builds up between the outer wall and O-rings of the cartridge and the inner wall of the brass housing. The sediment creates a rigid bond which freezes the cartridge inside the housing. Removing, or pulling, an old cartridge which is frozen inside a housing is an exceedingly difficult job. No simple and effective tool exists to pull frozen cartridges. One of the key objectives of the present invention is the easy and efficient removal of a Moen cartridge from a plumbing housing even in cases where the cartridge is frozen inside the housing.
There are a number of tools considered to be cartridge pullers which are actually designed to pull the core only. The user is often alarmed when the core comes out and leaves the sleeve frozen inside the housing. Without the use of a well designed sleeve puller, a frozen sleeve is impossible for a do-it-yourselfer or handyman to remove. This is especially critical in the case of a shower valve where the water to the dwelling cannot be turned back on until the cartridge is replaced. Some do-it-yourselfers and handymen have resorted to breaking through the shower wall to replace the housing itself. More commonly, a plumber is called for an emergency visit to fix the problem.
A tool frequently used to pull a cartridge is one which is supplied by Moen. This tool is a core puller but is often sold as a cartridge puller. The Moen core puller has a cylindrical body with indexing tabs at one end and a T-handle at the opposite end. The indexing tabs serve to center the tool on the housing and locate it against the opposite tabs on the end of the cartridge. A bolt down the centerline of the cylindrical body engages the thread in the core and a large nut threadably attached to the outside of the body presses against the rim of the housing. The T-handle is held stationary and a large wrench is used to advance the nut against the rim of the housing. Sometimes, the entire cartridge is pulled out, but more often just the core is pulled out. This tool is an effective core puller, but can not pull the complete cartridge when the sleeve is frozen inside the housing.
Rucker, U.S. Pat. No. 6,929,024 discloses a secondary tool to be added to the Moen tool for pulling the sleeve. Rucker discloses a large custom-design tap which is attached to the end of the Moen tool and used to cut threads into the wall of the sleeve. The tapping process is unfamiliar to most do-it-yourselfers and is difficult to perform. The tapping process also has the problem of creating metal shreds which could easily pass through the holes in the sides of the sleeve and lodge between the sleeve and housing. These metal shreds are likely to cause damage to the wall of the housing during the pulling process.
Frozen sleeves generally require a twisting motion to break up the rigid sediment between the sleeve and the wall of the housing. Sharp left-and-right twisting is much superior to direct outward pulling for the removal of the sleeve. The Moen tool with the added tap by Rucker does not have the capability of applying strong left-and-right twisting forces to the sleeve. In the case of a moderately frozen sleeve, pulling hard with this tool will probably strip the threads and leave the sleeve frozen inside the housing. The Rucker sleeve pulling tool is expensive, requires mechanical skills, may cause damage to the housing, and is subject to failure.
A tool for pulling both core and sleeve is disclosed by Hseu, U.S. Pat. No. 5,119,556. The Hseu tool uses a cylinder slidably engaged on a threaded rod. A flat handle is threaded onto the rod above the cylinder. On the rod below the cylinder is a thin oval washer and below the washer is a stop which is threaded on near the bottom end of the rod to retain the washer. Below the stop is a thread which engages the thread in the core. The tool is attached to the core and the cylinder is placed against the rim of the housing. The threaded handle is advanced along the rod and presses on the cylinder to create a pulling force on the core. To operate this tool, the cylinder must be held against the rim of the housing, the handle must be turned and the threaded rod must be held to prevent it from turning. The operation of the Hseu tool is awkward and requires significant dexterity.
Once the core is removed, the handle and cylinder are removed from the rod and a second tool with a biased magnet to hold the oval washer at an angle is slid onto the rod. This tool is used to push the washer into the sleeve and move it up and down until the washer flatly engages under an internal ledge within the sleeve. The biased magnet is removed and the flat handle and cylinder are reassembled to the rod. Pulling force is then applied as before by holding the cylinder, turning the handle and holding the threaded rod so that it does not turn. In most cases, the strength of this tool will not be sufficient to pull the sleeve. Most likely, the threads on the tool will strip or the oval washer will fail and release the tool. As explained above, frozen sleeves usually require twisting forces to break them free. Direct outward pulling is generally not enough to dislodge a frozen sleeve and often results in a broken tool or damaged plumbing. The Hseu tool can not provide twisting forces. Without this capability, the Hseu tool is not a complete solution to the removal of a Moen cartridge. Furthermore, the Hseu tool is complicated, weak and unreliable.
The tool disclosed by Seminario, U.S. Pat. No. 3,952,394, is a better tool for cartridge pulling, but it suffers from a number of problems which are solved by the present invention. Seminario shows a core pulling device which is difficult to use. Seminario suggests that the core be removed by a “relative rotation of the (threaded) rod and the bar” of the tool. This is difficult to accomplish because a cylinder must be held in contact with the rim of the housing and the threaded rod must be prevented from turning while the bar is rotated. This is an awkward operation and is similar to the Hseu tool.
The present invention which consists of a core puller, a sleeve puller and a handle, greatly simplifies the process of pulling a core by using a novel and unique combination left-hand/right-hand thread design on the core puller. A left-hand screw with a smaller right-hand screw attached at the leading end and a handle attached at the following end is threaded through the core puller body. Then the right-hand screw is threaded into the right-hand thread in the core. The handle is turned clockwise so that the left-hand screw moves outwardly from the core puller body and at the same time, the right-hand screw tightens into the core. This pulls the core outwardly from the sleeve and continued turning of the handle removes the core completely.
The right-hand/left-hand thread design is additionally unique in that it allows the screw to attach rigidly to both the core puller and to the core itself. The resultant rigid coupling between the core puller and the core automatically aligns, centers and supports the core puller on the housing. Turning the handle with one hand is all that is required to remove the core. Both the Hseu and Seminario tools require the operator to hold a sleeve against the rim of the housing, keep a threaded rod from turning and turn a handle all at once in order to pull the core. This is a complicated three-hand procedure which is much inferior to the simple one-hand procedure of the present invention.
Once the core is removed, Seminario shows a method of removing the sleeve by gripping the inside of the sleeve with a tubular tool containing expansible knurled segments at one end. The tool is inserted into the frozen sleeve and a conical expander is drawn into the tool to force the knurled areas of the expansible segments into contact with the wall of the sleeve. Unfortunately, with his design only the very tips of the segments make contact with the wall. Seminario uses a tapered pressure ring at the ends of the segments in an attempt to gain more contact with the sleeve. However, the taper does not work as desired. The taper at the end of the tool matches the taper of the conical expander and does little more than securely press the very ends of the segments into the sleeve wall. The reason for this is that the segments are extremely stiff and will not flex with the pressure of the expander. The tool itself is made of hardened steel, the segments are curved circumferentially and the segments have a substantial wall thickness. These factors all make the segments extremely stiff lengthwise. The Seminario segments can not bend to permit the knurled grip to achieve full contact with the sleeve and the majority of the knurled surface has little or no contact with the wall. As a result, only limited twisting force may be applied to the Seminario tool before it slips. Although the Seminario sleeve puller is an improvement over the other prior art references described herein, it remains flawed because it lacks the gripping power needed to quickly and effectively free a frozen sleeve.
The problem of inadequate gripping power is overcome in the present invention by using expansible segments featuring two novel and unique innovations. First, the rigid expansible segments are made to be somewhat flexible. This is accomplished in the preferred embodiment by cutting a slot around the circumference of the segments and creating a flexible member on each segment. Second, the pressure ring against which the expander presses is recessed inside the end of the tool. The pressure ring is provided in the preferred embodiment by cutting a recessed step inside the end of the tool directly beneath the knurled grip. This allows the conical expander to exert a more uniform outwardly expansive pressure on the knurled areas of the segments. As a result of this more uniform outwardly expansive pressure, the flexible members on the segments bend and the knurl is pressed flatly against the sleeve.
These innovations provide approximately 10 times as much contact area between the knurl and the sleeve as does the Seminario tool. Since gripping power is directly proportional to the area of contact between the knurl and the sleeve, the present invention provides approximately 10 times as much gripping power as the Seminario tool.
Finally, it is noted here that even after a sleeve is broken free of the housing by applying sharp twisting forces, a significant percentage of sleeves remain extremely resistant to pulling. This is because the sleeve has four O-rings sealing it to the housing, and in most cases, these O-rings are frozen to the housing. Three of the O-rings are mounted perpendicular to the axis of the sleeve, referred to as the perpendicular O-rings, and one is at an oblique angle, referred to as the oblique O-ring. Twisting the sleeve breaks the oblique O-ring from the housing, but does not free the perpendicular O-rings. The sleeve rotates inside the perpendicular O-rings and they remain bonded to the housing. In these cases, a “final pull” is required to break the perpendicular O-rings from the housing.
Although the Seminario tool can apply twisting forces and break the sleeve and the oblique O-ring free from the housing, it does not have a separate provision for performing a final pull in cases where the perpendicular O-rings remain frozen. In these cases, it is up to the operator to pull with enough strength to break the perpendicular O-rings free. Many operators will not be able to do this manually and will need additional help or other tools to finish the job of pulling the sleeve. The Seminario tool is significantly deficient in that it does not provide for a final pull.
This deficiency is cured in the present invention by uniquely combining the tasks of the core puller and the sleeve puller by assembling the two separate elements of the cartridge puller into a combined tool to perform a strong final pull. This is accomplished by attaching the core puller to the end of the sleeve puller and pulling the sleeve puller and sleeve together in much the same manner as pulling a core. This task may be accomplished by a worker of average strength and skill.
It is estimated that about 10 percent of all Moen cartridges can be completely removed by pulling on the core and removing both the core and sleeve in one piece. In cases where the sleeve remains frozen inside the housing, the difficulty of removing the sleeve varies from moderate to severe. No existing tool provides a sure and simple method of removal in all cases.
Consequently, a need exists for a tool which is inexpensive, a tool which is safe and easy to use, a tool which removes both the core and the sleeve of the cartridge, a tool which is fast, a tool which can be used by do-it-yourselfers and a tool which works every time. The present invention accomplishes these objectives.